Discussions about AI have a distinctly 1950s feel about them, and it's about time we stopped using the term "artificial" in AI altogether. What we really mean is "Designed Intelligence" (DI). In popular parlance, words like "artificial" and "machine" are used in contra-distinction to "natural", and carry overtones of metallic robots, electronic circuits and digital computers as opposed to living, pulsing, thinking biological organisms. The idea of a metallic contraption with wired innards having rights or disobeying human laws is not only chilling, it is absurd. But that is emphatically not the way that DI is heading.
Very soon the distinction between artificial and natural will melt away. Designed Intelligence will increasingly rely on synthetic biology and organic fabrication, in which neural circuitry will be grown from genetically modified cells, and spontaneously self-assemble into networks of functional modules. Initially, the designers will be humans, but very soon they will be replaced by altogether smarter DI systems themselves, triggering a runaway process of complexification. Unlike in the case of human brains, which are only loosely coupled via communication channels, DI systems will be directly and comprehensively coupled, abolishing any concept of individual "selves" and raising the level of cognitive activity ("thinking") to unprecedented heights. It is possible (just) that some of this designed bio-circuitry will incorporate quantum effects, moving towards Frank Wilczek's notion of "quintelligence". Such entities will be so far removed from the realm of human individual thinking and its accompanying qualia that almost all the traditional questions asked about the opportunities and dangers of AI will be transcended.
What about humans in all this? Only ethical barriers stand in the way of augmenting human intelligence using similar technology, in the manner long considered by the transhumanism movement. Genetically modified humans with augmented brains could elevate and improve the human experience dramatically.
There are then three possible futures, each with its own ethical challenges. In one, humans hold back from enhancement because of ethical concerns, and agree to subordinate their hegemony to DI. In the second scenario, instead of sidelining themselves, humans modify their brains (and bodies) using the same technology, and subsequently hand over this enhancement management to DI, achieving a type of superhuman status that can exist alongside (yet remain inferior to) DI. Finally, one can imagine DI and AHI (augmented human intelligence) merging at some point in the future.
In the event that we are not alone in the universe, we should not expect to communicate with intelligent beings of the traditional sci-fi flesh-and-blood sort, but with a multi-million-year old DI of unimaginable intellectual power and incomprehensible agenda.